Accounts obtained for the prominent Edinburgh funds boutique, revealed that turnover had plunged by 32% to £3.5m during the 2012 calendar year.
This the company blamed in part on the loss of revenue from its £60m SVM UK Active Fund after the investment trust's liquidation in the summer of 2011 following a hostile takeover by Alaska-based investor Stewart Horejsi's Cyrun vehicle.
Its 2013 performance is also likely to be muted after SVM saw the £111m SVM Global investment trust defect to Henderson Global Investors earlier this year.
Mr McLean said of 2012: "It is fair to say it was tough and we are repositioning the business and have been over the last year and are still doing that now."
SVM's operating loss for the year widened from £55,000 for 2011 to £1.6m due to the fall in income.
Mr McLean said the focus of the firm he founded in 1990 is now on open-ended funds, noting that investments trusts, of which SVM still has one, are expensive for a funds house to administer.
He said that its repositioning has led to a 21% rise in fund inflows year-on-year.
"There are steady fund inflows there," he said. "We expect over the next year that will replace the earnings and assets that we need."
SVM's troubles in the investment trust market have seen its assets under management fall to £450m. This compares to close to £700m just two years ago.
Mr McLean said that the SVM World Equity fund run by fellow director Neil Veitch had been particularly successful in attracting assets. However, it was still worth just £16.7m at the end of July, according to the latest figures from SVM.
Mr McLean said that the £82.3m UK Growth fund run by his SVM co-founder and partner Margaret Lawson had also been selling well.
But he acknowledged that whatever the success of its repositioning, earnings for 2013 will be affected by the loss of its two main investment trusts.
"It won't come through this year," he said of SVM's reshaping.
SVM, which was previously called Scottish Value, will remain focused on managing equity mandates, Mr McLean said.
He insisted that there is still a place for smaller funds houses in a UK funds space dominated by large institutions.
"Clients benefit as long as we are delivering a service for them and they have achieved good performances in the short and long term," he said.
He believes that medium-sized firms get squeezed between the smaller specialists, such as SVM, and the might of the bigger houses.
"We are quite a focused business," he said, noting its focus on UK, global and European equity mandates.
"We are not trying to cover the waterfront in asset classes," he added.
He maintained SVM has a good balance sheet as it invests its own assets through its Highlander hedge fund and vehicles such as SVM's UK Emerging Fund, which does not show in its profit and loss accounts.
SVM's accounts for 2012 showed that investments held by the group, largely listed shares, fell from £9.3m to £7.7m during the year.
Net assets dropped from £21.5m to £18m last year, the accounts revealed, while net cash at the house fell from £12.5m to £9.3m.
SVM's directors said in their report attached to the accounts: "With shareholders' funds of £17,986,000 at 31 December 2012, the group remains in a strong position to face the future."
The bulk of SVM's shares are owned by Mr McLean and Ms Lawson although other staff members, of which there was an average of 25 last year, also own shares.
The company paid a £20,000 dividend last year.
The highest paid director, which is assumed to be Mr McLean, received emoluments of £182,000, up £10,000 on 2011.
SVM recently signed a deal with State Street to consolidate all of its UK-based fund administration activities including global custody and investment accounting.